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APPLICATION FILED APR. 6, 1915.

1,201,366. Patented 001111916.

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' current. pressure of the foot will cause contact UNITED sTATEs PATENT oEEroE.

WILLIAM GENTRY SHELTON, OF NEW YORK, N. Y.

ELECTRIC SWITCH.

Application filed April 6, 1915.

To all whom 'it may concern Be it known that I, IVILLIAM GENTRY Sl-IELToN, a citizen of the United Sta-tes of America, residing in the borough of Manhattan, city, county, and Statel of New York, have inventedy certain new and useful Improvements in Electric Switches, of which the following is a specification.

This invention relates to portable electric switches and has for anl object to provide a foot-controlled variable resistance switch of small dimensions and light weight.

The invention is particularly intended for use in connection with portable electric engines, for instance hand engines, wherein it is desired to control the speed or power oi the engine by frequent regulation ofthe The device is designed so that through the highest resistance and a slight turning movement of the foot will gradually cut out the resistance. A release of the foot at whatever point the switch has been turned to will immediately open the circuit.

In the drawings accompanying this specification, one practicable embodiment of the invention is illustrated. In such drawings,-Figure l is a cross-section taken on about the plane ofthe line 1 1, Fig. 3. Fig. 2 is a cross-section at about right angles to the plane of the section of Fig. 1, the plane being indicated by the line 2 2 in Fig. 3. Fig. 3 is an underside view of the top or movable portion of theV device, and Fig. 4L is a top view of the bottom portion of the device.

rlhe switch is intended for use in connection with electrically operated instruments, such, for instance, as massage vibrators and dental engines. Although it is adapted for use with permanently installed mechanism, it is most convenient, owing to its size and capabilities of control, for small portable outfits. Not only is it capable of ready transportation from place to place, but it is also capable of being moved from place toj'place in the operating room, as for instance", from one part of the room to another, or from one side of the patient to the other. Vherever the operator desires to stand, he may there move the switch and place it in a convenient position for engagement with the ball of his foot. Being strong in construction, it will withstand any amount of pressure which the operator finds Specification of Letters Patent.

Patented Oct. 17, 1916.

Serial No. 19,533.

necessary to place upon that foot for the support of his body, and, it being of small thickness, the foot will not be wearicd by resting upon the switch.

The lower part 1 of the switch casing is intended for resting upon the floor and is provided on its lower portion with an anti-friction surface, as for instance, a sheet of rubber 2. This will permit oi' the switch being shoved from place to place by the footof the operator, but will hold it in position during the application of operating pressure. rIhe electric cable 3 is shown led into the bottom portion 1. It is preferable to have the cable led into the bottom portion because this will remain substantially stationary during the rotary movement of the part which is engaged by the foot,

namely, the upper portion l. The upper Y portion l is also shown provided with an anti-friction surface afforded by a rubber covering o. The two portions 1 and'el constitute a housing lor the switch portions. A series oi balls 6 running in suitable grooves is illustrated for preventing friction when the parts are pressed to the limit of the down movement of the upper member. Suitable brushes 7 are shown carried by the lower member l in proper position to contact with the commutators S carried by the upper kportion or member l. The brushes are shown connected by means of wires E) with the cable 3, and the commutator segments are Vshown connected by means of Wires 10- with the rheostat elements -11 which are mounted in some suitable manner on the upper or movable member L1.

Suitable means are provided for normally holding thev brushes 7 out of engagement with the commntators S, and the device is also so constructed that when the upper member is relieved of pressure it will return to initial position, which is preferably with the brushes over those portions of the commutators which are connected with the highest resistance. In the present instance a single coiled compression spring l2 is used for this purpose. A pivot 13 is shown riveted to the upper member 4 and mounted in a boss 14 in the lower member 1. A cotter 15 is in the lower end of the pin 13 to limit the upward movement of the upper member and to prevent disasscmblage of the parts. In the illustration the rubber sheet 2 covers the chambered out portion in which the end of the pin 13 and the cotter are located, thus making not only a neat appearance, but a covering which will prevent the dust raised from the floor by manipulation of the switch, from' gaining access to the interior parts. It will be seen that the spring 12 has one end, 16, fastened to the upper plate by being seated in a suitable hole therein, and the other end 17 similarly engaging the lower plate. Thus, the same spring will serve to separate the parts when relieved from pressure, thereby drawing the commutators out of engagement with the brushes, and will also rotatively rotate the parts to initial positions.

It will be. understood that the switch shown and described is illustrative of the invention, and changes in construction may be made within the terms of the claims without `departing from the spirit of the invention.

lVhat I claim is:

1. In a footcontrolled variable resistance switch, the combination with two members rotatable and reciprocable one relatively to the` other, one of the said members being adapted to rest upon the `tloor and the other to receive the :toot of the operator, and resistance devices associated therewith, the parts being so orga-nized that relative reciprocation of such members closes and opensI the'circuit and relative rotation when the circuit is closed varies the resistance, and a coiled compression spring connected to said members and vadapted to normally hold the same in the open circuit and greatest resistance ositions.

2. a device of the character speeied, the'combination with a lower member, an electric cable leading into such member, a pair of brushes carried by such member and connected to the cable, an upper member mounted for rotation relatively thereto, a resistance device and commutatore carried Copies of this patent may be obtained for thereby, a4 coiled compression spring connected to said members and adapted to normally hold the brushes out of contact with the commutatore and the parts in their initial position, and the lower portion of the lower member and the upper portion of the upper member being provided' with antifriction faces.

3. In a device of the character specified, the combination with a lower member, an electric cable -leading into such member, a pair of brushes carried by such member and connected to the cable, an upper member mounted ior rotation relatively thereto, a resistance device and commutatore carried thereby, and a. coiled compression spring connected to said members and adapted to normally hold the brushes out of contact with the commutators and the parts in their initial position.

4. In a device of the character specified, the combination with a lower member, an electric cable leading into such member, a pair of brushes carried by such member and connected to the cable, an upper member mounted for rotation relatively thereto, a, resistance device and commutators carried thereby, a coiled compression spring connected to said members and adapted to normally hold the brushes out of contact with the commutators and the parts in their initial position, and rubber facings mounted on the vlower portion of the lower member and the upper portion of the upper member.

In witness whereof, I have hereunto signed my name in the pei-sence of two subscribing witnesses.

WILLIAM GENTE-Y SI-IELTON.

Vitnesses- GEO. W, STUART, CHAs. LYON RUSSELL.

ve cents each, by addressing the Commissioner of Patents, Washington, D. CJ 

